It's interesting that the Bezos "factory" plan and the Musk settlement plan suffer from opposite problems. Bezos offers a cash flow (it's the reason it's there in the first place) but no option to expand to permanence. Has anyone moved to live on an abandoned oil rig (serious questions. sounds possible if you wanted to. but..) ? How self sufficient are they? How much money does it take to live there per month? while Musk's plan has a vision, but otherwise no real reason to stay other than the vision.

However, settlements have sprung up around mines, railroads, etc. So building up the infrastructure on the 'half way to anywhere' point, aka LEO, will allow us to make the next step affordable: find things that are worth bringing back. If those things happen to be far enough out (and still valuable enough to bring them back), that is the point where people go to stay. The only option of 'permanence' history has ever known. Look up at the cities troughout history, from Alexander to the America's. No matter how self sufficient they are, if they don't have something of value to keep people from leaving, preferably other than being the only one left, they will die out sooner rather than later.

Not really. The modern form of humans have been around for about 200,000 years, and the Earth has been around for 4.5 billions years.

So from that standpoint a century or two is not very long at all.

There are various scenarios for trouble with Earth. Some can arise with very little warning and very few options to do anything about them. Some require such concerted action by so many that they are virtually impossible to stop. In that case a few centuries is too long.

Neither Musk nor Bezos are doing what they are doing because they feel catastrophe is imminent, so stop creating artificial schedules and need dates just to make things look bad.

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You are taking a very narrow view of what Musk's goal is. In order to be successfully multi-planetary we don't have to rely on just Mars, or just Earth's Moon. We just can't rely on Earth being around. So a Mars population might have to rely on supplies from outside of Mars in order to survive on it's own, and that's OK.

Well AFAIK only Musk has been talking about settlement IE people, eventually whole families living on another body in the solar system and not returning. By definition everyone else is talking "bases" or "factories."

Bezos and Musk are talking about high level goals, so of course they are not detailing every single movement of a human. And they would admit that they don't really know how everything will roll out.

For instance, in order to have factories in space it might turn out that we'll have colonies in space too (likely aboard artificial gravity stations). Now Bezos doesn't talk about that, but he hasn't ruled it out either.

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From our experience of Arctic and Antarctic bases none of those would survive without constant replenishment from more temperate areas.

By law both the Arctic and Antarctic are only for scientific use, not industrial or private industry. So drawing conclusions about a future on Mars based on our experiences here on Earth is fraught with bad analogies.

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Yes it would be wonderful if enough settlements were established throughout the solar system that their resources were diverse enough to set up inter-settlement trade but there is no evidence for anyone planning that on anything like the scale needed.

Yet with only the high level plans of Bezos and Musk you are making assumptions about what the details would be about their plans - even though you have not spoken with them.

If asked, I think both Bezos and Musk would not rule out anything at this point, since they are both knowledgeable enough about history to know that the future can unfold in surprising ways. Meaning it's too early to rule out anything...

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If we don't continuously lower the cost to access space, how are we ever going to afford to expand humanity out into space?

Neither Musk nor Bezos are doing what they are doing because they feel catastrophe is imminent, so stop creating artificial schedules and need dates just to make things look bad.

There's always plenty of time, until there isn't.

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Bezos and Musk are talking about high level goals, so of course they are not detailing every single movement of a human. And they would admit that they don't really know how everything will roll out.

For instance, in order to have factories in space it might turn out that we'll have colonies in space too (likely aboard artificial gravity stations). Now Bezos doesn't talk about that, but he hasn't ruled it out either.

So everything that's not ruled out is possible? Could be? Might be? Perhaps we could just go with what he's said and done?

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By law both the Arctic and Antarctic are only for scientific use, not industrial or private industry. So drawing conclusions about a future on Mars based on our experiences here on Earth is fraught with bad analogies.

Perhaps, but outside of Apollo, Skylab and ISS they are the only analogies we have. No analogy should be pushed too far however.

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Yet with only the high level plans of Bezos and Musk you are making assumptions about what the details would be about their plans - even though you have not spoken with them.

Have you? If you haven't and you're not telepathic the only way to know what he's thinking is to listen to what he says and see what he does. So far Blue has done some test flying and said he'd like to see a million people living in space. So would I, but I've no idea how to do it, although lowering the launch price by about an order of magnitude would be a good idea.

But AFAIK that is an aspiration, not a plan.

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If asked, I think both Bezos and Musk would not rule out anything at this point, since they are both knowledgeable enough about history to know that the future can unfold in surprising ways. Meaning it's too early to rule out anything...

In theory perhaps.

IRL every stop you take opens up a set of options on the "possibility tree" and closes off others. As Blue progress they will have to commit to a course of action.

Keep in mind 1000 000 people means how many New Glenn flights at about 6 at a time? From how many launch sites?

« Last Edit: 11/18/2016 08:26 AM by john smith 19 »

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Every time someone speculates about the future plans of Blue or SX or someone else and they add additional things to those plans that represents something else that has to happen for that plan to go ahead as you would want it.

I suggest that anyone doing so should consider the probability that the thing you want to happen will actually happen.

For instance (and OT for this thread) I'd like Bezos to implement this idea as a pair of captured NEO's which spin at either end of longish line to give reasonable gravity and plenty of work space and ultimately plenty of living room. The start of a O'Neillian space settlement. They'd be found by the telescopes currently on NEO search duties and brought in by special probes that would smooth the surfaces and take the resulting dust as reaction mass for a solar powered mass driver to make the necessary course and delta v changes. Fully reusable and using all in space resources and ready to repeat the process once it's ion drive (used to get to the NEO in the first place) was refueled.

But IRL the odds on bet is it will be a set of modules bought up from Earth as a mini station with zero g throughout, possibly from Bigelow, as they seem to give the best volume for launch mass.

"But that's so crude, so lacking in vision" some might say.

Unfortunately that's also the simplest, lowest risk and (when you factor in the substantial development costs for my specialist vehicles to process the asteroids and the tether) cheapest option.

So which would you rather bet on to get done? My approach may never be implemented but the other way is fully viable now if you have a viable transport system (which is what Blue are working on) and valuable enough product, specialized glasses for FO amplifiers and sensors seems close or at the right price per unit mass.

I just ask whenever someone comes up with some neat idea (like using an in space power reactor) they consider the cost and risk that will add to the original plan. You may have just turned a viable $500m project into a $10.5Bn unviable project.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Every time someone speculates about the future plans of Blue or SX or someone else and they add additional things to those plans that represents something else that has to happen for that plan to go ahead as you would want it.

I suggest that anyone doing so should consider the probability that the thing you want to happen will actually happen.

I think most of us do, to some degree, but since there is no standard for calculating the unknown future, it would be hard to judge how well anyone is calculating probabilities.

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For instance (and OT for this thread) I'd like Bezos to implement this idea as a pair of captured NEO's which spin at either end of longish line to give reasonable gravity and plenty of work space and ultimately plenty of living room. The start of a O'Neillian space settlement.... [snip]

But IRL the odds on bet is it will be a set of modules bought up from Earth as a mini station with zero g throughout, possibly from Bigelow, as they seem to give the best volume for launch mass.

"But that's so crude, so lacking in vision" some might say.

I'm pretty sure most people that have a realistic idea about how things COULD unfold in the future (which I count myself part of) would NOT say it's crude or lacking in vision.

In fact I would say what Jeff Bezos wants is what we would call "vision", but "how" it gets done is details. But you could have someone that focuses just on artificial gravity, and what their solution would be could be "visionary", yet how the bathrooms work on such a rotating station would just be "details". So there is a hierarchy.

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I just ask whenever someone comes up with some neat idea (like using an in space power reactor) they consider the cost and risk that will add to the original plan. You may have just turned a viable $500m project into a $10.5Bn unviable project.

Sorry, but you are attempting to throttle enthusiasm, and that doesn't sit well with people, especially when no one knows what will happen in the future.

You could just ignore those that you feel are clearly speculating irrationally? Might make your life easier...

I think most of us do, to some degree, but since there is no standard for calculating the unknown future, it would be hard to judge how well anyone is calculating probabilities.

That's not quite true though is it? You can certainly say that "likelyhood" is inversely proportional to the cost of doing something and the risk and the amount of new technology needed.(to the doers, their surroundings and their neighbours).

So building a LOX/RP1 of X 1000 lb thrust has a certain likelyhood.Building a NTR of X 1000 lb thrust has a certain (lower) likelyhoodBuilding an anti-matter rocket of X 1000 lb thrust has a certain (lower) likelyhood still.

All are (theoretically) possible but the probability of success ranges from strong in the short term to just about possible in the far future.

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I'm pretty sure most people that have a realistic idea about how things COULD unfold in the future (which I count myself part of) would NOT say it's crude or lacking in vision.

It delivers only what is needed in space to directly carry out the direct goal. It will leave nothing in space that can be used to expand into space. It's pretty much the baseline for any crewed "space factory" concept from the 1970's.

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In fact I would say what Jeff Bezos wants is what we would call "vision", but "how" it gets done is details. But you could have someone that focuses just on artificial gravity, and what their solution would be could be "visionary", yet how the bathrooms work on such a rotating station would just be "details". So there is a hierarchy.

A want without a plan is basically an aspiration. That's a hope, and depending on (again) the probability of it happening ranges from this-time-next-year to "Hail Mary pass."

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Sorry, but you are attempting to throttle enthusiasm, and that doesn't sit well with people, especially when no one knows what will happen in the future.

I love enthusiasm, along with imagination. But I prefer both to grounded in the known.

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You could just ignore those that you feel are clearly speculating irrationally? Might make your life easier...

I already do.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Step 1: a cheap $/kg SHLV vehicle to transport bulk, people and other things to LEO, etc.

Step 2: what makes business sense when using #1.

The business cases that could show up in step 2 is an open question because until you have #1 the evaluation as to what makes business sense is unknown.

The obvious answer is of course a corporation that concludes it can only make a decent return on its investment by putting a very big payload into orbit and is also willing to fund the development of the LV to do so.

It's a variation on the "What's big enough yet impossible to sub divide to fit on smaller LV's so that SLS has to be used" question.

All I could come up with was a)Very large reflecting telescopes and b)MW sized (and above) nuclear reactors.

I guess the nearest to this would be the USG's need for "Liberty ships" to move a shedload of cargo across the Atlantic.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Both Musk and Bezos want a future where humans are genuinely spacefaring. In the longer term that means there are more human descendants living off the earth than on it. It implies people making a living in a wide range of niches off the earth. Among other things that makes life in general and human descendants in particular harder to extinguish.

The only difference is whether starting from basically nothing, it's better to try to kickstart it in near earth space with a goal of O'Neill like habitats or on another planet. They've got both covered. Both are about getting so many people making a home off of the earth that spacefaring is irrevocable. Both have a sense of urgency that the window of opportunity to do this may not remain open indefinitely.

A million people at 6 passengers a time on 1 vehicle is 16 666 flights. At 1 flight a day from 1 pad that's 457 years.

With 10 vehicles from 10 launch pads and 5 flights per day/pad (IE pad refurb in < 5 hrs) you can do it in less than 1 year. That's 24/7/365 operation.

Better make sure those pads don't have any close neighbours.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Do both. Colonize and develop other planets and heavenly bodies and also use space for heavy industry so that perhaps just maybe we can clean up the Earth.

Both of these things can be enabled by efficient reliable low cost access to both LEO and deep space, therefore it doesn't matter what the differences of vision are, the more companies and other entities working on the problem the better.

NG would be capable of 20-30 passengers. ITS 200-300, New Armstrong 100+?. Still going to take a few 1000 launches.

At 100 passengers a time that's 10 000 launches

Still a lot of launches.

Basically that stretch of sea under the flight path will be permanently off limits.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Then again, modern air travel has reached ~100k airline flights worldwide every single day.

Rocket flights are a lot harder, but 10k flights within a decade or two should be possible to do by the time you really make reusable rockets practical and reliable and assuming there is an economic motivation to do it. Flipping it the other way around, it "only" requires a launch cadence on the order of one a day.

« Last Edit: 11/27/2016 07:56 PM by Nilof »

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For a variable Isp spacecraft running at constant power and constant acceleration, the mass ratio is linear in delta-v. Δv = ve0(MR-1). Or equivalently: Δv = vef PMF. Also, this is energy-optimal for a fixed delta-v and mass ratio.

Then again, modern air travel has reached ~100k airline flights worldwide every single day.

A point the designers of Skylon were well aware of.

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assuming there is an economic motivation to do it.

That's the biggest joker in the pack.

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Flipping it the other way around, it "only" requires a launch cadence on the order of one a day.

Over what period were you counting?

If New Glenn is good for a 100 passengers that's 10 000 flights.

To move 1 000 000 people in a year to LEO with 10 vehicles takes 10 pads and a pad refurb time of 8 3/4 hours.

You appear to have increased vehicle capacity by a factor of 3.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

Chris Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

As far as why a large SHLV is better vs a small LV is the mechanics of launch costs. There are many items that have fixed costs no matter the LV size. And other items that are almost so trivial in costs related to size they do not affect the end costs. But a semi-reusable LV that lowers the cost factor relative to size makes the fixed values more significant. Such that using larger LVs will lower the $/kg without having to work hard at lowering the costs. Other items also are incentives for going large and that is the cube rate for volume vs the square rate for costs of LVs. Volume controls the relative LV performance. Meaning with all other things equal a larger LV (up to a point for the manufacturing limits not requiring different methods) a larger LV will offer significantly lower $/kg prices than smaller LVs.

As far as why a large SHLV is better vs a small LV is the mechanics of launch costs. There are many items that have fixed costs no matter the LV size. And other items that are almost so trivial in costs related to size they do not affect the end costs. But a semi-reusable LV that lowers the cost factor relative to size makes the fixed values more significant. Such that using larger LVs will lower the $/kg without having to work hard at lowering the costs. Other items also are incentives for going large and that is the cube rate for volume vs the square rate for costs of LVs. Volume controls the relative LV performance. Meaning with all other things equal a larger LV (up to a point for the manufacturing limits not requiring different methods) a larger LV will offer significantly lower $/kg prices than smaller LVs.

As Jess Sponable noted during the DC-X project you need to be very careful with how cost scales with the square or the cube of length (in any direction). Larger surface area gives a bigger TPS but can also give lower per unit mass, hence higher entry and easier TPS requirements.

Lowering the $/lb was basically the Saturn V approach and the SLS approach. I'd agree scaling up is not as tough as some think, as long as you're below the intrinsic size limits of the mfg hardware but you still end up with a big absolute launch price instead. A vehicle putting 16 tonnes into LEO for 62m. A vehicle that can put 160 tonnes into orbit for $160m is 1/3 the cost per Kg if fully used. Otherwise it's about 3x the cost for the same 16 tonne payload.

True, things like range costs and GNC are about the same regardless of what TSTO is sitting on a pad.

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BFS. The worlds first Methane fueled FFORSC engined CFRP structured A380 sized aerospaceplane tail sitter capable of flying in Earth and Mars atmospheres. BFR. The worlds biggest Methane fueled FFORSC engined CFRP structured booster for BFS. First flight to Mars by end of 2022. Forward looking statements. T&C apply. Believe no one. Run your own numbers. So, you are going to Mars to start a better life? Picture it in your mind. Now say what it is out loud.

As far as why a large SHLV is better vs a small LV is the mechanics of launch costs. There are many items that have fixed costs no matter the LV size. And other items that are almost so trivial in costs related to size they do not affect the end costs. But a semi-reusable LV that lowers the cost factor relative to size makes the fixed values more significant. Such that using larger LVs will lower the $/kg without having to work hard at lowering the costs. Other items also are incentives for going large and that is the cube rate for volume vs the square rate for costs of LVs. Volume controls the relative LV performance. Meaning with all other things equal a larger LV (up to a point for the manufacturing limits not requiring different methods) a larger LV will offer significantly lower $/kg prices than smaller LVs.

As Jess Sponable noted during the DC-X project you need to be very careful with how cost scales with the square or the cube of length (in any direction). Larger surface area gives a bigger TPS but can also give lower per unit mass, hence higher entry and easier TPS requirements.

Lowering the $/lb was basically the Saturn V approach and the SLS approach. I'd agree scaling up is not as tough as some think, as long as you're below the intrinsic size limits of the mfg hardware but you still end up with a big absolute launch price instead. A vehicle putting 16 tonnes into LEO for 62m. A vehicle that can put 160 tonnes into orbit for $160m is 1/3 the cost per Kg if fully used. Otherwise it's about 3x the cost for the same 16 tonne payload.

True, things like range costs and GNC are about the same regardless of what TSTO is sitting on a pad.

It comes down to what are the goals1) independent orbits of small (<10mt) satellites2) bulk cargo and personnel to the same orbit (space station) or planetary body

For the 1st case a medium or medium heavy launcher may be the best fit.For the 2nd case an SHLV where the more the better both for initially putting up the station and then support for a the large >12 person station.

Jeff Bezos goals align with the second case. Elon Musk's goals also align with the 2nd goal with the 1st goal only a signpost on the road to get there.

Both Jeff's and Elon's goals are enormous undertakings with no guarantees of success. In particular the economic viability of both are a huge unknown.

For example, can we afford the investment needed to get in space manufacturing to the point it can reasonably replace Earth based equivalents? Perhaps mining NEOs might generate a return to enable this but again completely unproven at this point.

In terms of technology development, being near Earth in my view allows a more incremental approach, due to support from Earth, ease of personnel rotation etc.

It's an interesting debate but I think too little data yet to conclude much. To me all that matters right now is that there are people with considerable will, means and growing track records in space who are going to give it a go. That is unprecedented and in uncertain times is both inspiring and gives me hope for the future.